This invention relates to respirator face masks, and more particularly to such face masks for use with intermittent positive pressure breathing ("IPPB") apparatuses.
Many individuals who suffer from respiratory disease or respiratory ailments require breathing assistance from mechanical ventilators. For example, patients with chronic obstructive lung disease approaching respiratory failure due to muscular fatigue could be allowed to rest their respiratory muscles by receiving intermittent positive pressure breathing (IPPB) treatment. Such patients do poorly when mechanically ventilated after tracheal intubation.
During conventional IPPB, a breathing gas is conveyed by a ventilator to a respirator face mask which is held in place over a patient's face and which communicates with a patient's airway. As pressure is increased inside the face mask during inspiration, a net force is generated on the mask which tends to separate the mask and its peripheral sealing edges from the face. Such separating force decreases the contact pressure between the mask and the skin and potentiates air leaks. To create and maintain a sufficient seal, current masks are pressed against the face by a continuous force, such as may be established by an elastic band extending around the patient's head. The force used to maintain such a seal often exceeds capillary pressure and results in the development of skin necrosis and pressure sores. A lower contact pressure, however, generally does not create a sufficient seal during inspiration, and results in unacceptable air leaks.
It would be desirable to provide a respirator face mask, for use with IPPB apparatuses, which maintains a sufficient seal with a patient's face, but does not exert an excessive, constant force which could result in skin necrosis and/or pressure sores.
Accordingly, it is an object of the invention to provide a respirator face mask which does not exert a constant, damaging force on a patient's face. It is another object of the invention to provide a respirator face mask which forms an adequate seal with a patient's face, but does not cause skin necrosis or pressure sores. A further object of the invention is to provide a respirator face mask which is self-sealing in response to positive ventilation pressure. Other objects and advantages of the invention will be apparent to one skilled in the art upon reading the following disclosure.